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Biomedical subjects

H Weber

Publications and source records attributed to H Weber.

At least 541 records · Page 30Linked to original sources
PubMed1978

Refined molecular weights for phage, viral and ribosomal RNA.

The RNAs of the Escherichia coli bacteriophages MS2 and Qbeta as well as E. coli 16S ribosomal RNA were examined under identical conditions by electron microscopy using the protein-free benzyldimethylalkylammonium chloride (BAC) spreading technique. From the contour length ratios of the RNAs and the known number of nucleotides for MS2, the chain lengths for Qbeta RNA and 16S RNA were found to be 4790 +/- 150 and 1645 +/- 55 nucleotides. Correcting for the base composition of Qbeta RNA the molecular weight of the Na salt of this RNA is (1.64 +/- 0.06) . 10(6) daltons. Since published values on the relative lengths of Qbeta RNA and several other homogeneous RNAs (E. coli 23S rRNA, E. Coli bacteriophage R17 and f2 RNAs, Pseudomonas aeruginosa phage PP7 RNA and Newcastle disease virus RNA) are available, we are able to calculate the approximate number of nucleotides for these useful standards.

Coliphages↗
PubMed1978

[Corrected transposition of the great arteries: surgical treatment of associated cardiac defects (author's transl)].

Corrected transposition of the great arteries is often associated with other cardiac anomalies. We report our experience with the correction of the associated cardiac defects in 13 cases: ventricular septal defect with pulmonary hypertension (5 cases), ventricular septal defect with obstruction of pulmonary outflow tract (5 cases), obstruction of pulmonary outflow tract (2 cases), ostium primum defect (1 case). The possible surgical approaches for repair of the cardiac anomalies are described and the results of the operative correction are communicated. Precise diagnosis, the knowledge of the unusual disposition of the conducting tissues and new surgical approaches are prerequisite for successful correction.

Adult↗
PubMed1978

Essential Sulfhydryl Group in the Transport-catalyzing Protein of the Hexose-Proton Cotransport System of Chlorella.

The polyene antibiotic nystatin transforms the sugar-proton contransport system of Chlorella to a mere facilitated diffusion system. This experimental condition was used to test the sugar-translocating unit of the active uptake system for possible essential sulfhydryl groups. It could be shown that the catalyzed translocation of sugar is sensitive to the sulfhydryl-reactive compound N-ethylmaleimide. Sugar flow by passive leak as induced by the detergent Triton X-100 is not affected by sulfhydryl reagents. These results show that the sugar-translocating carrier protein possesses a sulfhydryl group, which is essential for its function.

Journal Article↗
PubMed1978

Vasopressin responsiveness of renal adenylate cyclase in newborn rats and rabbits.

Newborns show an inability to concentrate maximally their urine. The vasopressin responsiveness of adenylate cyclase was, therefore, examined in membranes obtained from kidneys of neonatal and adult rats and from renal medulla and isolated collecting tubules of newborn and adult rabbits. In spite of higher basal and NaF-stimulated activity, vasopressin failed to stimulate adenylate cyclase from neonatal rat kidneys. In neonatal and adult rabbits, basal and NaF-stimulated adenylate cyclase activities of renal medullary membranes were comparable but vasopressin stimulation was significantly lower in the newborns. No change in hormonal activation constant was observed. This hyporesponsiveness of neonatal adenylate cyclase to vasopressin was confirmed with single isolated rabbit collecting tubules for adenylate cyclase determination, a highly sensitive preparation. It is intriguing to speculate that the low vasopressin stimulation of the medullary adenylate cyclase in the developing kidney may contribute to the known limitations of the urinary concentrating mechanism in the newborn period.

Adenylyl Cyclases↗
PubMed1978

[Circadian variations in the frequency of arrhythmia and quantitative analysis of rhythm disturbances].

In 29 patients with long term ECG monitoring the circadian rhythm of extrasystoles was investigated. A decrease of maximal frequency of extrasystoles was calculated for each hour and an increase of the minima during night was detected. In 77% of the patients also for 6 hour-segments a circadian rhythm could be calculated. The effect of the antiarrhythmic treatment on the frequency of extrasystoles was different depending on the frequency of the sinus rhythm.

Anti-Arrhythmia Agents↗